2. Food supplements. 2.1. Supplementation of prebiotics and probiotics.

Level of recommendation	Statement
A	Background: Data from partly large-scale, randomized, double-blind intervention studies consistently show no preventive effects of prebiotics and probiotics for the endpoints allergic rhinitis and bronchial asthma. The vast majority of current intervention studies also show no preventive effect of supplementation with prebiotics and/or probiotics on atopic eczema.
	Recommendation: Prebiotics and/or probiotics should not be given to pregnant women or infants for the purpose of allergy prevention, not even as part of infant formula. (A)
Level of evidence	Boyle 2016 (1++); Abrahamsson 2013 (1+); Allen 2014 (1++); Loo 2014 (1+); Bertelsen 2014 (2++); Peldan 2017 (1++); Wickens 2013 and 2018a (1++); Wickens 2018b (1+); Ranucci 2018 (1++); Sierra 2015 (1++); Wopereis 2018 (1+); Lundelin 2017 (1+); Cabana 2017 (1-); Niinivirta 2014 (2+); Simpson 2015 (1-); Ro 2017 (1++); Hrdy 2018 (2+); Rutten 2015 (1+); Kim 2015 (1+); Murphy 2019 (1+)
Level of consensus:	Consensus